Reviews — R. Kidston's Catalogue, Fossil Plants. 179 



Mr. Carruthers has also figured a specimen of Halonia attached to Lepidophloios} 

 which is in the Collection. The conclusion arrived at by him was very similar to 

 that mentioned by Feistmantel, that Halonia was only a condition of Lepidophloios. 

 Both on the Halonian-branch and the main stem of this example some of the 

 characteristic leaf-scars of Lepidophloios are shown. Tbose on the Halonia portion 

 are normal in form and point downwards, but on the main stem from some cause, 

 perbaps pressure or distortion daring or after mineralization, the leaf-scars are 

 arranged at right angles to the direction they ordinarily hold on the stem ; hence the 

 two lateral angles of the leaf-scar lie parallel to the direction of growth, and the scar 

 of the vascular bundle so twisted round, occupies one of the lateral angles. 



In his last memoir on the " Organization of Fossil Plants of the Coal Measures," 2 

 Dr. Williamson gives a figure (pi. xxxiv.) of Halonia attached to a Lycopodiaceous 

 stem. He says, 3 " In my second memoir (Phil. Trans. 1872, p. 222), read in June, 

 1871, I said, 'I have little doubt but that Halonia was a fruiting branch of a 

 Lepidodendron ; ' and in a note added in April, 1872. I affirmed absolutely, 'First, that 

 Halonia belongs to the upper branches of a Lepidodendroid tree, consequently it 

 cannot be a root ; ' ' secondly, we learn that Halonia is a specialized branch of a 

 Lepidodendroid tree that is not itself a Halonia.'" . . . "The specimen now 

 described is unquestionably not a Lomatophloios, but a true Lepidodendron." In 

 describing his specimen, he says further (p. 468), that at the lower portion of the 

 branch the leaf-scars have exactly the same form as those of L. selaqinoides and L. 

 elec/ans, Lindley and Hutton. I have already mentioned that the leaf-scars on the 

 specimen described by Mr. Carruthers are so turned round on the stem that instead of 

 their greater diameter being transverse to the stem, as is normally the case in 

 Lepidophloios, it is vertical. Dr. Williamson's figure does not show clearly the form 

 of the scars further than that the vertical diameter of those on the lower part of the 

 stem seems greater than their transverse breadth. The leaf-scars towards the upper 

 portions of the specimen are rhomboidal. I am inclined to think there is here a case 

 of distorted leaf-scars on the lower part of the fossil, similar to that occurring in 

 Mr. Carruthers' specimen, where, notwithstanding this peculiarity, the fossil is 

 clearly identifiable as Lepidophloios laricinus. 



With such an imperfectly preserved example as Dr. Williamson's appears to be, 

 any conclusion derived from it is of doubtful value, and though from an examination 

 of his plate one cannot affirm his fossil is a Lepidophloios, equally one cannot say it 

 is a Lepidodendron. 



The figures given by Feistmantel and Dr. Macfarlane are conclusively affirmative 

 that at least some Halonia specimens belong to Lepid"phloios, whereas we have no 

 example which shows in an undoubted manner that any Halonia fossil can be referred 

 to Lepidodendron. My own opinion is that Halonia is exclusively related to Lepido- 

 phloios as its fruiting branch. Of course, those authors who place Lepidophloios 

 laricinus, Sternberg, in Lepidodendron, may consistently say that Halonia is the fruit- 

 ing branch of Lepidodendron, but I am not aware that any recent writer has followed 

 this classification. 



Lepidophloios and Lepidodendron I regard as essentially distinct genera. Lomato- 

 phloios is now united with Lepidophloios, hence I understand Dr. Williamson's state- 

 ment that " The specimen now described is unquestionably not a Lomatophloios, but 

 a true Lepidodendron," which is equivalent to saying that it is not a Lepidophloios, but 

 a Lepidodendron. 



Sigillaria Menardi, Goldenberg (Flora Sarsep. Foss. pi. vii. fig. 1), appears to be 

 referable to L. laricinus. The central point of the leaf-scars of this figure is 

 probably the tubercle with which the leaf-supporting pedicels of this plant are 

 frequently provided, as pointed out by Weiss. TJ. tumidum, Carr., the type of 

 which is in the Collection, is, I think, also referable to L. laricinus. The leaf-scars 

 are not well preserved on his type, but it probably finds its place here. It is not, at 

 any rate, a telodendron as defined by Lindley and Hutton, for it shows more than two 

 rows of the larger scars on the circumference of the stem, a third row appearing on 

 the side not shown in Mr. Carruthers' figure. 



Halonia tuberctdata, Eichwald (Lethsca Rossica, vol. i. p. 148, pi. xi.), is another 

 instructive example as illustrating the affinities of Halonia. The core out of this 

 specimen is a typical Halonia, the impression Lepidophloios. In such examples as 



1 Geol. Mag. Vol. X. April, 1873. 2 Phil. Trans. 1883, clxxiv. p. 459. 3 I.e. p. 469. 



